Back in high school, we took a tour of the Savannah River Site (this was allowed in the late 70's). We saw things mostly by driving by in a tour bus, but we did get to go into a few buildings, and try out a remote manipulator system (harder than it looks to get good with it).

The relevant part was the waste processing area, which had a smokestack (presumably for power). Painted eighty or a hundred feet up was a large stripe. The guide said that that was how deep they were going to bury the building once it had reached end of life.

Having just watched "Beneath the Planet of the Apes" I could imagine a future where explorers go down the stack because they were attracted by the 50+ feet that would remain above ground. Curiosity is hard to fight.